Preparation of Patterned BiFeO3 Thin Films on the Functional Silicon Substrates Surface

2012 ◽  
Vol 512-515 ◽  
pp. 1731-1735
Author(s):  
Guo Qiang Tan ◽  
Meng Cheng ◽  
Yan Wang ◽  
Lei Cheng ◽  
Ao Xia

Patterned octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs) was fabricated on silicon substrates, utilizing short wave UV irradiation meter (λ=184.9nm) as the photolithograph apparatus under the cover of the photomask. The patterned BiFeO3 were prepared on the functional OTS-SAMs by sol-gel method. The characterization of the samples patterns was carried out by various techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and energy disperse spectroscopy (EDS). The results indicate that the pattern BiFeO3 thin films were successfully prepared on the functional OTS-SAMs by sol-gel method and the thin films were BiFeO3 thin films with hexagonal perovskite distorted structure which has clear boundaries and 200µm deposited lines width.

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.


2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.


2007 ◽  
Vol 14 (06) ◽  
pp. 1181-1185 ◽  
Author(s):  
ENLING LI ◽  
XUEWEN WANG ◽  
SHANSHAN WANG ◽  
GUICAN CHEN

Gallium nitride ( GaN ) nanocrystalline powder has been prepared by sol–gel method. The GaN powder has been confirmed as single-crystalline GaN with wurtzite structure by X-ray diffraction (XRD) and selected-area electron diffraction (SAED), and the diameter of the grains of GaN powder changes from 30 to 100 nm under transmission electron microscopy (TEM). Having been excited by 240 nm light at room temperature, GaN powder has a strong luminescence peak located at 395 nm and a weak luminescence peak located at 295 nm, attributed to GaN band-edge emission and blue-shift of the band-gap emission. Moreover, X-ray photoelectron spectroscopy (XPS) confirms the formation of the bond between Ga and N , and Raman scattering spectrum confirms A1 (TO) and E1 (TO) vibrational modes of GaN .


2016 ◽  
Vol 680 ◽  
pp. 193-197
Author(s):  
San Ti Yi ◽  
Si Qin Zhao

TiO2, 1%La/TiO2, 1%Ce/TiO2 and a series of Laand Ce co-doped TiO2 photocatalysts were prepared by sol-gel method. Using sol-gel method combine with hydrothermal method prepared rare earth La, Ce and nitrogen co-doped TiO2 photocatalysts. The microstructure, spectroscopy performance and ion doped form of prepared samples were characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy techniques and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of doped TiO2 were examined by measuring the photodegradation of methyl orange. The results showed that the products were all anatase TiO2 nano powder, doping Laor Cehinder the growth of TiO2 particle, further more, doping Laand Cetogether hinder the growth of TiO2 particle more effective, doping N broaden the light response range of TiO2 photocatalyst. At the same time, the photocatalytic activity results indicated that the prepared samples showed superior UV light photocatalytic activity, the sample 1% (La:Ce,9:1)-N/TiO2 showed the highest UV-vis photocatalytic activity.


2007 ◽  
Vol 280-283 ◽  
pp. 839-844
Author(s):  
Hui Qing Fan

Relaxor-based 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) thin films were grown epitaxially on silicon substrates by sol-gel method and PbO cover coat technique, and investigated by x-ray diffraction, auger electron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The phase development and microstrure evolution of the PMN-PT film were significantly affected by the final annealing temperature and time. A perovskite PMN-PT film was obtained after annealing at 850oC for 1 min. Then, highly <100>-oriented and textured PMN-PT films could be achieved by using a LaNiO3 perovskite template.


Author(s):  
Ming-Yuan Shen ◽  
Chen-Feng Kuan ◽  
Hsu-Chiang Kuan ◽  
Cing-Yu Ke ◽  
Chin- Lung Chiang*

This study used the sol–gel method to synthesize a non-halogenated hyperbranched flame retardant containing nitrogen, phosphorus and silicon, HBNPSi, which was then added to a polyurethane (PU) matrix to form an organic–inorganic hybrid material. Using 29Si nuclear magnetic resonance, energy-dispersive X-ray spectroscopy of P- and Si-mapping, scanning electron microscopy, and X-ray photoelectron spectroscopy, this study determined the organic and inorganic dispersity, morphology, and flame retardance mechanism of the hybrid material. The condensation density of the hybrid material PU/HBNPSi was found to be 74.4%. High condensation density indicates a dense network structure of the material. The P- and Si-mapping showed that adding inorganic additives in quantities of either 20% or 40% results in homogeneous dispersion of the inorganic fillers in the polymer matrix without agglomeration, indicating that the organic and inorganic phases had excellent compatibility. In the burning test, adding HBNPSi to PU resulted in the material passing the UL-94 standard at the V2 level, unlike the pristine PU, which did not meet the standard. The results demonstrated that after non-halogenated flame retardant was added to PU, the material’s flammability and dripping were lower, thereby proving that flame retardants containing elements such as nitrogen, phosphorus, and silicon exert an excellent flame retardant synergistic effect.


Author(s):  
Helena Bruncková ◽  
Ľubomír Medvecký ◽  
Pavol Hvizdoš ◽  
Juraj Ďurišin

2012 ◽  
Vol 545 ◽  
pp. 148-152
Author(s):  
Jaafar Mohd Hilmi ◽  
Rusdi Roshidah ◽  
Mohamed Nor Sabirin ◽  
Rosiyah Yahya ◽  
Norlida Kamarulzaman

One of the aspects most intensively researched in the continuing improvisation of lithium battery is the search for high capacity, high energy density and high performance cathode materials. Substitution of the electroactive elements with heteroatoms is one of the promising methods. In this study, a potential cathode material with a layered structure was successfully synthesized via a sol-gel method. As a comparison, the well-known LiMn1/3Co1/3Ni1/3O2(LiMn0.333Co0.333Ni0.333O2) was also synthesized using exactly the same method and conditions. Both materials were characterized using simultaneous thermogravimetric analysis (STA), X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). The stoichiometries of the compounds were also confirmed through energy-dispersive X-ray spectroscopy (EDX) measurement. XRD results show that both compounds are single phase and impurity-free with well-ordered hexagonal layered structure characteristics of R-3m space group. Both compounds also show similar morphologies with well-formed crystals and clean surfaces as depicted by the SEM images. XPS measurement reveals that the introduction of chromium into LiMn1/3Co1/3Ni1/3O2results in a considerable change in the chemical environment as observed by significant changes in the binding energies (BE) of manganese, cobalt and nickel respectively.


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